Deployment devices are used to deploy prostheses and in particular prostheses incorporating self expanding stents within lumens in the human body. This invention will generally be discussed in relation to the deployment of prostheses within the aorta but the invention is not so limited and may be used for other of deployment sites as well.
In some forms of deployment device trigger wires are used to retrain a prosthesis in a particular position on a deployment device or to retain self expanding stents of the prosthesis in a retracted state. In the region of the deployment device in which the prosthesis is carried, trigger wires can foul or catch with stents on the deployment device, particularly when the deployment device is bent to pass through convolutions in the lumen, therefore causing inaccurate deployment and perhaps jamming or breakage of the trigger wire.
Throughout this specification the term distal with respect to a prosthesis and a deployment device for prosthesis is the end of the prosthesis or deployment device which in use is furthest away in the direction of blood flow from the heart and the term proximal refers to the end of the prosthesis or deployment device which in use is nearest to the heart. When applied to other vessels corresponding terms such as caudal and cranial should be understood.
It is the object of this invention to provide an arrangement by which a trigger wire on a deployment device can be more safely routed to its destination or to at least provide a practitioner with a useful alternative.